Sary Arka Copper Processing in Kazakhstan recently commissioned a suite of custom designed products from Northern Ireland’s Telestack to use in a complete truck-receive, material transfer and heap leaching application for stacking copper ore. The company states: “Heap leaching has experienced exponential growth over the last decade as mining companies seek to increase efficiencies in an increasingly limited supply of ores globally. Mobile equipment provided by Telestack are an ideal option offering flexibility coupled with custom-designed features without the large upfront costs or high running costs typically found in more traditional methods of heap leaching. The additional benefits of reducing traffic across the site, the ability to containerise the equipment after the end of the project, coupled with a high resale value, the Telestack equipment are an ideal solution for the operator who seeks an immediate yet reliable solution.”
In this application Sary Arka sought the expertise of Telestack to help achieve maximum production rates whilst keeping production costs low. The two stage installation comprised a Titan T800-6 tracked Truck Unloader, three TCL831 tracked conveyors, a HIC830 tracked Horizontal Index Conveyor and a TS850 tracked Radial Telescopic Stacker and are used in a heap leaching application to stockpile copper ore at rates of up to 800 t/h.
Stage 1 of the application involves two independent Metso Outotec crushing plants working at 400 t/h. Each plant continuously feed two lines of 40 t rigid trucks directly via a storage hopper. Each truck draws the raw material from the crushing plant and reverses onto earth ramps to feed the Titan T800-6 tracked Truck Unloader. The 800 t/h unit is a track mounted unit that can easily be relocated around the site and is fitted with a Cat C4.4 diesel engine.
The Telestack truck unloader was fitted with a heavy duty apron chain belt feeder (winterised belting to -30°) which ensures the surge of material discharging from the truck can be transferred in a regulated and controlled manner. The chain and sprocket driven apron belt ensures that there is no stalling or slipping of the feeder compared to regular “roller-type” belt feeders. The flared 6 mm abro-lined reception hopper means that it has the capacity to accept abrasive material such as copper ore from trucks or loaders.
The steel apron bars can absorb the material surge and impact and the flexible side seal skirting and ventilated chassis allows any material to be released, thus protecting the chain and belt. The adjustable material levelling blade on the incline of the feeder helps control the flow of material before it transfers onto the 10 m heavy duty lattice incline. Stage 2 of the application involves the copper ore fed onto a series of three TCL831 track mounted conveyors which are used to keep the trucks off the heap leach pad to prevent damage to the neoprene layer. Each unit incorporates hydraulic adjustment at the rear and front of each unit to adjust transfer heights accordingly.
Each unit is 31 m long (105 ft) and is capable of conveying 800 t/h+. To ensure that the unit would be fully functional throughout the year at temperatures ranging from -30° temperatures, Telestack incorporated several features including winterised belting, winterised grease and bearings, low temperature hydraulic oil, heaters in hydraulic tanks, winterised seals on hydraulic rams and insulated control panels complete with thermostat controlled heater.
The TCL831 conveyors transfer the copper ore onto a HIC830 track-mounted Horizontal Index Conveyor. This unit enables continuous feed to the stacking conveyor and minimises the amount of movement required to produce a linear stockpile of approximately 100 m wide. The copper ore is then fed onto a TS850 track-mounted Radial Telescopic Stacker. This final unit of the system is a 46 m radial telescopic stacker which stockpiles the copper ore to a height of 14 m at 18°. The unit has six various stockpile programmes including “flat top” stacking mode, however, the unit can also be operated via the radio remote control.
The TS850 also included a heater and insulation in the control panel alongside winter proof cables and wiring throughout the machine and includes double radial wheels with two CWD 2050 wheel drive and wide flotation tyres. The suite of units are currently producing a capacity of 2.4 Mt+ per annum and are proving to be an integral part of the post processing phase of the operation.
